Dear Guido,
Yes, volcanic eruptions that inject SO2 into the stratosphere cool Earth
and cause Northern Hemisphere winter warming in the first winter after
tropical eruptions. Hansen et al. (1979) is correct, and Jim has been a
pioneer in studying the effects of volcanic eruptions on climate.
Canty et al. (2013) made a fundamental error in counting the cooling by
volcanic eruptions twice, as I pointed out here:
https://www.atmos-chem-phys-discuss.net/12/C10686/2012/acpd-12-C10686-2012.pdf
Driscoll et al. (2012) diluted the volcanic signal by including many
small eruptions and looking at two winters following each eruption. By
looking at only large eruptions and one winter, we show a clear signal in:
Zambri, Brian, and Alan Robock, 2016: Winter warming and summer
monsoon reduction after volcanic eruptions in Coupled Model
Intercomparison Project 5 (CMIP5) simulations. /Geophys. Res.
Lett./, *43*, 10,920-10,928, doi:10.1002/2016GL070460.
and
Zambri, Brian, Allegra N. LeGrande, Alan Robock, and Joanna
Slawinska, 2017: Northern Hemisphere winter warming and summer
monsoon reduction after volcanic eruptions over the last millennium.
/J. Geophys. Res. Atmos./, *122*, 7971-7989, doi:10.1002/2017JD026728.
Fujiwara et al. (2015) find *stratospheric *warming after the three most
recent eruptions, consistent with previous work. Why mention it?
Wunderlich and Mitchell (2017) actually do find a positive NAO and
tropical cooling after large eruptions, so I don't understand why you
even mention that paper either.
So you have brought up two papers that agree with Hansen et al. (1979)
and conventional wisdom, and two with fundamental problems.
Alan
Alan Robock, Distinguished Professor
Editor, Reviews of Geophysics
Department of Environmental Sciences Phone: +1-848-932-5751
Rutgers University Fax: +1-732-932-8644
14 College Farm Road E-mail: [email protected]
New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock
☮ http://twitter.com/AlanRobock 2017 Nobel Peace Prize to ICAN!
Watch my 18 min TEDx talk at http://www.youtube.com/watch?v=qsrEk1oZ-54
On 12/1/2017 4:08 AM, Guido Visconti wrote:
Hello all
but the eruptions really cool? Read the papers
Wunderlich, F., & Mitchell, D. M. (2017). Revisiting the observed
surface climate response to large volcanic eruptions. Atmospheric
Chemistry and Physics, 17(1), 485-499. DOI: 10.5194/acp-17-485-2017ù
Fujiwara, M., Hibino, T., Mehta, S. K., Gray, L., Mitchell, D., &
Anstey, J. (2015) Global temperature response to the major volcanic
eruptions in multiple reanalysis data sets. Atmospheric Chemistry and
Physics, 15, 13507–13518.
Canty, T., Mascioli, N. R., Smarte, M. D., & Salawitch, R. J. (2013)
An empirical model of global climate-Part 1: A critical evaluation of
volcanic cooling. Atmospheric Chemistry and Physics,13, 3997.
Driscoll, S., Bozzo, A., Gray, L.J., Robock, A. and G. Stenchikov
(2012) Coupled Model Intercomparison Project 5 (CMIP5) simulations, of
climate following volcanic eruptions, J. Geophys. Res., 117, D17105,
doi:10.1029/2012JD01760
In view of these the paper by Jin Hansen et al.(Hansen, J. E.,Wang,W.
C., and A.A. Lacis, (1978) Mount Agung eruption providestest of a
global climatic perturbation.Science, 199, 1065-1068, DOI
10.1126/science.199.4333. 1065)
should be at least withdrawn
Guido Visconti
Il giorno 01 dic 2017, alle ore 06:41, Paul Beckwith
<[email protected] <mailto:[email protected]>> ha scritto:
Hello Alan,
For Mount St. Helens in 1980, wasn’t the main reason for the lack of
climate impact the fact that the explosive energy was mostly directed
horizontally as opposed to upwards, so that minimal sulfur amounts
reached the stratosphere. I thought that there was significant sulfur
released from the eruption, but that it mostly stayed in the troposphere.
Sincerely,
Paul
-----Original Message-----
From: [email protected]
<mailto:[email protected]>
[mailto:[email protected]] On Behalf Of Alan Robock
Sent: Thursday, November 30, 2017 11:27 PM
To: [email protected] <mailto:[email protected]>;
geoengineering
Subject: Re: [geo] VEI vs cooling
There is a positive correlation, but VEI is not a good index. It is
an estimate of the explosive energy, not the amount of sulfur
injected into the stratosphere, which is what determines the climate
impact. Mount St. Helens in 1980 was VEI 5, very explosive, but had
little SO2 and no climate impact. See the discussion on pp.
11551-11553 of my paper,
http://climate.envsci.rutgers.edu/pdf/RobockFree95JD00825.pdf
Alan
Alan Robock, Distinguished Professor
Editor, Reviews of Geophysics
Department of Environmental Sciences Phone: +1-848-932-5751
Rutgers University Fax: +1-732-932-8644
14 College Farm Road E-mail:
[email protected] <mailto:[email protected]>
New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock
<http://envsci.rutgers.edu/%7Erobock>
☮ http://twitter.com/AlanRobock 2017 Nobel Peace Prize to ICAN!
Watch my 18 min TEDx talk at http://www.youtube.com/watch?v=qsrEk1oZ-54
On 11/30/2017 10:21 PM, David Appell wrote:
SRM people:
Does a volcanic eruption's VEI correlate to the amount of cooling it
will/can cause?
David
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